• Environmental Engineering Research
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• v.13 no.2
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• pp.51-65
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• 2008

The increasing demand for energy in the near future has created strong motivation for environmentally clean alternative energy resources. Microbial fuel cells (MFCs) have opened up new ways of utilizing renewable energy sources. MFCs are devices that convert the chemical energy in the organic compounds to electrical energy through microbial catalysis at the anode under anaerobic conditions, and the reduction of a terminal electron acceptor, most preferentially oxygen, at the cathode. Due to the rapid advances in MFC-based technology over the last decade, the currently achievable MFC power production has increased by several orders of magnitude, and niche applications have been extended into a variety of areas. Newly emerging concepts with alternative materials for electrodes and catalysts as well as innovative designs have made MFCs promising technologies. Aerobic bacteria can also be used as cathode catalysts. This is an encouraging finding because not only biofouling on the cathode is unavoidable in the prolonged-run MFCs but also noble catalysts can be substituted with aerobic bacteria. This article discusses some of the recent advances in MFCs with an emphasis on the performance, materials, microbial community structures and applications beyond electricity generation.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1073-1085
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• 2012

Soil microbial communities are immensely diverse and complex with respect to species richness and community size. These communities play essential roles in agricultural soil because they are responsible for most of the nutrient cycles in the soil and influence the plant diversity and productivity. However, the majority of these microbes remain uncharacterized because of poor culturability. Next-generation sequencing techniques have revolutionized many areas of biology by providing cheaper and faster alternatives to Sanger sequencing. Among them, amplicon pyrosequencing is a powerful tool developed by 454 Life Sciences for assessing the diversity of complex microbial communities by sequencing PCR products or amplicons. This review summarizes the current opinions in amplicon sequencing of soil microbial communities, and provides practical guidance and advice on sequence quality control, aligning, clustering, OTU- and taxon-based analysis. The last section of this article includes a few representative studies conducted using amplicon pyrosequencing.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.83-91
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• 2015

Mine soil contamination by high levels of metal ions that prevents the successful vegetation poses a serious problem. In the study presented here, we used the microbial biocatalyst of urease producing bacterium Sporosarcina pasteurii or plant extract based BioNeutro-GEM (BNG) agent. The ability of the biocatalysts to bioremediate contaminated soil from abandoned mine was examined by solid-state composting vegetation under field conditions. Treatment of mine soil with the 2 biocatalysts for 5 months resulted in pH increase and electric conductivity reduction compared to untreated control. Further analyses revealed that the microbial catalysts also promoted the root and shoot growth to the untreated control during the vegetation treatments. After the Sporosarcina pasteurii or plant extract based BNG treatment, the microbial community change was monitored by culture-independent pyrosequencing. These results demonstrate that the microbial biocatalysts could potentially be used in the soil bioremediation from mine-impacted area.

• Journal of Soil and Groundwater Environment
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• v.26 no.4
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• pp.20-26
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• 2021

In this work, an indigenous microbial consortium was obtained by selectively cultivating microbes using a long-aged petroleum-contaminated soil (Kuwait) containing recalcitrant petroleum hydrocarbons. The obtained microbial consortium was able to grow on and degrade the remaining petroleum hydrocarbons which could not have been utilized by the indigenous microbes in the original Kuwait soil. The following microbial community analysis using 16S rRNA gene sequencing suggested that the enhanced degradation of the remaining recalcitrant petroleum hydrocarbons by the novel microbial consortium may have been attributed to the selected bacterial populations belonging to Bacillus, Burkholderia, Sphingobacterium, Lachnospiraceae, Prevotella, Haemophilus, Pseudomonas, and Neisseria.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.20-25
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• 2001

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1169-1175
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• 2011

The soil chemical properties, microbial community structures and biochemical properties of lettuce or cucumber-cultivated greenhouse soil samples were analyzed to assess soil health and characterize microbial distribution in 8 locations in Korea. Although most of chemical properties were within the soil management guidelines, the available phosphate, and the contents of exchangeable potassium and calcium were higher than those of recommended levels. In the culture-dependent analysis, 841 bacterial strains were isolated from the greenhouse soils and were identified at the genus level by 16S rRNA gene sequences analysis. The dominant bacterial genera were Bacillus (35.7%), Microbacterium (9.3%), Arthrobacter (5.7%) and Lysobacter (5.1%). The abundance of pseudomonads was highly variable depending on the soil samples. In the culture-independent analysis, soil microbial community was investigated by using phospholipid fatty acid (PLFA) method. Principal component analysis (PCA) showed that a specific grouping for microbial community structure in the greenhouse soils was not observed based on cultivated crops and investigated sites. The results revealed that the greenhouses soils examined are relatively sound managed in terms of soil chemical contents and microbial properties.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.173-181
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• 2013

Livestock wastes are considered as major environmental pollutants because they contain high concentration of organic materials. In 2001, The Environmental Department reported that stock farmers were increasing as 5.1%/year, which resulted in a gradual increase in livestock wastes generation. The direct disposal of livestock wastes create several environmental problems. Thus, several countries banned the disposal of livestock wastes in environment including aquatic systems. Recently, aeration-based liquid fertilization was considered as potential way for the disposal of livestock wastes. In this study, next generation sequencing (NGS) analysis was used to understand the microbial community changes during liquid fertilization of livestock wastes. Microbial community was compared with liquid fertilizer physicochemical analysis such as $BOD_5$, $COD_{Mn}$ pH, N (Nitrogen), P (Phosphorus), K (Potassium) etc. The physicochemical parameters and bacterial community results pave the way for producing effective livestock-based fertilizer. By comparing the physical characteristics of the manure with microbial community changes, it is possible to optimize the conditions for producing effective fertilizer.

• Korean Journal of Veterinary Research
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• v.57 no.3
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• pp.159-167
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• 2017

The microbial community is known to have a key role during the rearing period of broilers. In this study, gut microbial composition and diversity were examined to evaluate the relationships between these factors and broiler growth performance. By applying 454-pyrosequencing of the V1-V3 regions of bacterial 16S rRNA genes, six fecal samples from four- and 28-day-old chickens from three broiler farms and 24 intestinal samples of broilers with heavy and light body weights were analyzed. Microbial composition assessment revealed Firmicutes to be the most prevalent phylum at farm A, while Proteobacteria were predominant at farms B and C. Fecal microbial richness and diversity indices gradually increased from four to 28 days at all three farms. Microbial diversity assessment revealed that small intestine microbial diversity was lower in heavy birds than in light birds. In light birds, the Firmicutes proportion was lower than that in heavy birds. In conclusion, each broiler farm revealed a specific microbial profile which varied with the age of the birds. The microbial communities appeared to affect growth performance; therefore, gut microbial profiles can be utilized to monitor growth performance at broiler farms.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.170-179
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• 2017

Tea is the most popular beverage in the world. In fact, there are mainly three different kinds of tea (Green tea, black tea, and post-fermented tea). Post-fermented tea is produced by the microbial fermentation process using sun-dried green tea leaves (Camellia sinensis) as the raw material. Chungtaejeon was a traditional tea introduced in the age of the ancient three states and is the only "Ddeok-cha or Don-cha" culture in the world that survived on the southwestern shore of Republic of Korea. In this study, the structures of the bacterial community involved in the production of oriental traditional post-fermented tea (Chungtaejeon) were investigated using 16S rRNA gene analysis. The 16S rRNA gene analysis of dominant microbial bacteria in post-fermented tea confirmed the presence of Pantoea sp., and Klebsiella oxytoca. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the post-fermented tea was ${\gamma}$-proteobacteria. As a result of the microbial community size analysis, it was confirmed that the size of the microbial communities of Chungtaejeon was the largest compared to other teas

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1310-1320
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• 2020

Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg^-1 super absorbent polymer, 3 g·kg^-1 humic acid, and 10 g·kg^-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.